CODEWITHSUNDEEP
clinuxsegmentation-faultsignalsipc
aaripaka prashad
aaripaka prashad

Reputation: 61

is an ambiguous behaviour for sigsegv

NOTE: SEGSEGV is blocked when I raised a SIGSEGV like, raise(SIGSEGV); but not on dereferencing of NULL pointer or memory violation. what is the issue here?

Code:

void sig_handler(int signo)
{
       psignal(signo,"i am in sig_handler\n");
}

int main()
{
    sigset_t intmask;
    int c = 0, *p = NULL;

    if((signal(SIGSEGV , sig_handler)) == SIG_ERR)
             perror("signal call is failed\n");
    if ((sigemptyset(&intmask) == -1) || (sigaddset(&intmask, SIGSEGV) == -1))    
          perror("Failed to initialize the signal mask");
    sigprocmask(SIG_BLOCK, &intmask, NULL);
    fprintf(stdout, "SIGINT signal blocked\n");
    c = *p;
}

Upvotes: 1

Views: 59

Answers (1)

unwind
unwind

Reputation: 399813

The manual page for sigprocmask() has the answer:

If SIGBUS, SIGFPE, SIGILL, or SIGSEGV are generated while they are blocked, the result is undefined, unless the signal was generated by kill(2), sigqueue(3), or raise(3).

Upvotes: 1

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